Apparatus for mixing and dispensing fluids of different densities



Dec. 11, 1945. D. J; CONWAY APPARATUS FOR MIXING AND DISPENSING FLUIDSOF DIFFERENT DENSITIES.

I Filed March 13, 1944 IN VEN TOR.

Patented Dec. 11, 1945 I APPARATUS FOR MIXING AND DISPENSING I FLUIDS OFDIFFERENT DENSITIES Donald J. Conway,'Cleveland, Ohio, assignor toAmerican Utilities Corporation,

Cleveland,

Ohio, a corporation of Delaware Application March 13, 1944, Serial No.526,222

- 6 Claims. (Cl. 62-1) This invention relates generally to an apparatusfor obtaining a definite proportional mixture of two fluids differing indensity and boiling points and for continuously dispensing the deflniteproportional mixture thus obtained for use in the industrial arts.

More particularly, the invention relates to an apparatus including atank or cylinder wherein -two fluids, capable of being admixed for usein metal operations (such as welding, cutting and the like) butdiffering in respect to their densities and boiling points, may be mixedin definite proportions and delivered continuously in such proportionsto the point of use until the contents of the cylinder shall have beenexhausted.

Still more limitedly, my invention contemplates an apparatus of thecharacter described wherein the fluid fuels consist of propane andether, the propane being charged into the cylinder under a pressure ofapproximately 100-410 pounds per square inch whereby it will be largelyconverted into a liquid and, in such form, will be admixed with theether of higher density in the bottom of th cylinder and, by means of atube leading from the bottom of the cylinder, a mixture of these liquidswill be delivered through the customary valve in the top of thecylinder.

Attempts have been made heretofore to dispense from cylinders a mixtureof predetermined proportions of these fluids and to maintain suchpredetermined proportions throughout the entire range of operation untilthe contents of the cylinders should be exhausted, utilizing for thispurpose tubes communicating'with the bottoms ,of the cylinders and thevalves in the tops of the same, but all such attempts with which I amfamiliar have resulted in failure. This failure has been due to thephysical properties of the propane which, as the pressure within thecylinders containing the same is reduced, tends increasingly to assume agaseous or vaporous form as the mixture is withdrawn from-the cylinders,with the result that a relatively large proportion of ether remains inthe cylinders after the exhaustion of the propane.

Due to the construction of the tube which communicates with the cylindervalve 'and to the manner in which the vaporous andliquid fuel elementsare admitted thereinto. I am enabled to obtain a mixture of definitepredetermined proportions of the fluid fuel ingredients and to insurethat this definite mixing and proportioning shall be automaticallymaintained so long as the pressure of the atmosphere within the tank-iscapable of delivering mixture through the said tube.

I accomplish these objects by means of the apparatus shown in theaccompanying drawing,

wherein Fig. 1 represents a view, partly in section and partly inelevation, of a cylinder having liquids of different densities thereinand provided with a mixing and dispensing tube constructed in accordancewith my invention; Fig.

2 an enlarged detail in section taken on the line 2--2 of Fig. 1 lookingin the direction of the arrows; Fig. 3 an enlarged detail in elevation,taken on the line 3-3 of Fig. 1 and lboking in the direction of thearrows; Fig. 4 an enlarged detail in section of the upper portion of themixing and dispensing tube; and Fig.5 an enlarged detail in sectionalelevation of the lower end of the dispensing tube.

Describing the various parts by reference characters, l0 denotes acylinder which is provided with a neck H within which there is threadedthe lower end of a valve body l2 of the type usually providedforcylinders suchas are'em-I The ployed for dispensing gases underpressure. threaded lower end l3 of the valve body is provided with achamber M from which a-port l5 leads to the usual valve seat (not shown)and with which the usual valve (notshown), having an operating handlel6, cooperates. The valve body'is provided with an elbow IT to which adise pensing pipe I8 is connected.

l9 denotes the delivery branch of a tube, the upper end of which isconnected, as by soldering or brazing, with the bottom of a tubularconnector 20, the upperend of said connector being shown as threadedinto the threaded lower end l3 of the valve body. It will be noted thatthis construction provides an expansion chamber between the delivery andof the branch l9 and the valve seat. The tube is bent upon itself toprovide a close return bend or loop-adjacent to the bottom of thecylinder, with-the delivery branch extending upwardly therefrom to theconnector.

:of which the tube is composed more ductile and less liabletocrystallize and break'otl within the cylinder. under rough usage. Thismannero! bending the tube also enables the latter to be inserted throughthe neck of the cylinder, when the valve is screwed thereinto.

The upper end of the branch 2| is shown as closed and an inlet opening22 ,is provided therein adjacent to the closed end thereof. 23 denotesan inlet opening slightly above the bottom of the looped lower end ofthe tube and located substantially axially beneath the portion of thebranch is extending thereabove. An inlet opening 24 is provided in thedelivery branch [9 above the level of the liquid and approximately inthe same horizontal plane as the center of the inlet opening 22.

In utilizing the apparatus thus described for dispensing a mixture ofether and propane, with an initial pressure in the cylinder ofapproximately 100 to 110 pounds at 70 F. atmospheric temperature andwith the dispensing tube inch internal diameter and the inlet openings23 and 24 made with a #69 drill and the inlet opening 22 of larger crosssectional area than the inlet openings 23 and 24, employing a cylinder38 inches high by 12 inches intemal diameter having therein a charge ofup to '7 pounds of ether and 50 pounds of propane, I have been able toproduce and to deliver through the cylinder valve a uniform mixture ofpredetermined definite proportions of either and propane until the levelof the liquid falls below the inlet opening 23. Satisfactory resultshave been obtained where the inlet opening 22 has been of a size such asmade by a #30 drill and also where it has been equal to'the crosssectional area of the interior of the tube.

It is believed that when the cylinder valve is opened the liquid in thebottom of the cylinder is delivered in a jet into the ascending branchIQ of the tube and that in so doing it is admixed with the vaporouscontents of the cylinder entering the descending branch of the tubethrough the inlet opening 22, the liquid delivered through the inletopening 23 exercising an aspirating or ejector action upon the vapor. Ihave found that the inlet opening 24 serves to balance the pressurebetween the gaseous or vaporous atmosphere in the tank and the mixturewithin the tube. When the valve I6 is opened slightly, so as todeliverthe mixture slowly through the branch IS, a back pressure will becreated within the tube which will be balanced by the pressure of theatmosphere above the liquid level transmitted through the inlet opening24. However, when the valve is opened wide and the mixture is beingwithdrawn rapidly from the tube, the pressure in the tube is reduced andthe inlet opening 24 serves to admit atmosphere from the cylinder intothe portion cf the tubular branch [9 thereabove, the net result beingthat the apparatus described herein delivers at all times a homogeneousmixture of the two fuels, admixed in constant, definite proportions; andthis delivery of such definite proportions persists until the level ofliquid within the cylinder falls below the inlet opening 23.Furthermore, with the parts constructed and arranged as described, thepressure within the cylinder falls very slowly, as compared withthe-conditions which exist in cylinders in which it has been attemptedheretofore to obtain a satisfactory operation of producing anddelivering a constant definitely proportioned mixture of propane andether.

Quite satisfactory results have also been obtained where, with a tube ofthe same diameter as that shown and described herein and with the inletopenings 22 and 23 of the respective sizes previously stated, the sizeof the inlet opening 24 has been increased by forming the same with a#62 drill and with a #54 drill. When, due to the operation' ofdispensing the mixture, the

pressure within the cylinder was insufiicient to effect any 'furtherdelivery therefrom, only 4 pound of ether remained therein in the formercase and approximately 1 pound of ether remained in the latter case.

Obviously the size of the inlet openings for the admission of liquid andvapor into the tube will vary with the cross sectional area of the tubeemployed and, while satisfactory results have been obtained by the use,in the particular apparatus described herein, of an inlet opening of thesize made by a #30 drill in the branch 2| of I the tube, the size ofthis opening may be reduced considerably but without preventing theconstant delivery of a satisfactory mixture of the vaporous and liquidcontents of the cylinder and, therefore, without avoiding the spirit ofmy invention.

Where one of the fluids within the cylinder remains in a liquidcondition throughout the entire operation of producing and delivering amixture of fluids and the other fluid remains in a gaseous conditionthroughout such entire operation, the opening 24 may be omitted.

Having thus described my invention, what I claim is:

1. An apparatus for the purpose specified including a cylinder fordispensing under pressure a mixture of liquids differing widely involatility and at least one of which exists normally in a gaseouscondition, the said cylinder being provided at its top with a deliveryvalve body, a tube comprising a delivery branch connected to andextending downwardly from the said valve body to a point in closeproximity to the bottom of the cylinder and a branch connected with theformer branch and extending upwardly from the latter to a point abovethe liquid level of a normally full charge of liquids within thecylinder, the delivery branch being provided with an inlet in the bottomthereof arranged for deliverin liquid substantially axially into thesaid delivery branch and. being provided with an inlet of substantiallythe same size above the said level and the opposite branch of the tubebeing provided with a relatively large inlet also located above the saidlevel.

2. An apparatus for the purpose specified including a cylinder fordispensing under pressure a mixture of liquids difiering widely involatility and at least one of which exists normally in a aseouscondition, the said cylinder being provided at its top with a deliveryvalve body, a tube comprising a delivery branch connected to andextending downwardly from the said valve body to a point in closeproximity to the bottom of the cylinder and a branch connected with theformer branch and extending upwardly from the latter to a point abovethe liquid level of a normally in claim 1, wherein, with a tube of theorder of 3/16 inch internal diameter, the inlet in the bottom of thedelivery branch has a cross-sectional area of approximately the size ofa hole made by a #69 drill, the inlet in the other branch having across-sectional area not materially less than that of a hole made by a#30 drill and the inlet in the portion of the delivery branch which isabove the said liquid level having a cross-sectional area ofapproximately the size made by utilizing a drill withinthe range of from#54 to #69.

4. A dispensing apparatus of the type set forth in claim 1, wherein,with a tube of the order of inch internal diameter, the inlets in thedelivery branch each have a cross-sectional area of approximately thesize of a hole made by a #69 drill and the inlet in the other branch hasa cross-sectional area not materially less than that of a hole made by a#30 drill.

,5. A dispensing apparatus of the type set forth in claim 2, wherein,with a tube of the order of inch internal diameter, the inlets in thedelivery branch each have a cross-sectional area of approximately thesize of a hole made by a #69 drill and the inlet in the other branch hasa cross sectional area not materially less than that of a hole made by a#30 drill.

6. An apparatus for the purpose specified including a cylinder fordispensing under pressure a mixture of fluid elements differing widelyin volatility, one of said elements existing normally in a gaseouscondition, the said cylinder being provided at its top with a deliveryvalve body, a tube comprising a delivery branch connected to andextending downwardly from the said valve body to a point in closeproximity to the bottom of the cylinder and a branch connected with theformer branch and extending upwardly from the latter to a point abovethe liquid level of a full charge of fluids within the cylinder, thedelivery branch being provided with an inlet in the bottom thereofarranged for delivering liquid substantially axially into the saiddelivery branch and the opposite branch of the tube being provided witha relatively large inlet located above the said liquid level,thefirst-mentioned inlet, in a tube wherein the delivery branch isapproximately 3/16 inch internal diameter, having a cross sectional areaof approximately the size of a hole made by a #69 drill.

DONALD J. CONWAY.

